It seems that you have a magic fabric here with this VaprThrm®

Posted on Jan 27, 2017

"I received the packages yesterday. Immediately went into the hills for the night to see how long I could remain comfortable in a bivy using a half sleeping bag and down parka, with your fleece socks and the triggs. FYI last night was the coldest night of the year. My therm measured 27 below at 4 AM. Needless to say, I was cold. Good news for you, however. My hands and feet survived and I never felt like frostbite was a threat. My feet were actually warm(they had the protection of a sleeping bag) and my hands were certainly comfortable. Keep in mind that my arms are exposed to the elements and not tucked in a sleeping bag! I brought the Altitude Mitts just in case, but didn't need them. It seems that you have a magic fabric here with this VaprThrm™. It's one of the most unusual things I've seen in recent years. I have a pair of OR expedition mitts (their top of the line model) and a bivy in these conditions, with those mitts, would have required me to pull my hands in my parka at the least. So, kudos! Things are looking good....it was a fun test!"